The present invention is a method for analyzing a small hydrocarbon sample to determine the composition of the sample. In particular, the sample is analyzed by a gas chromatograph and field ionization time of flight mass spectrometer.
Petroleum samples are complicated hydrocarbon mixtures containing paraffins, cyclic paraffins, multiring aromatics, and various heteroatomic hydrocarbons (most commonly O, S, and N). Virgin petroleum crude oils contain molecules of a wide boiling point range from highly volatile C4 hydrocarbons to nonvolatile asphaltenes. Analysis of petroleum composition of various boiling ranges is necessary for inputs to many subsequent processes.